The present invention relates generally to heat-transfer labels and relates more particularly to a new heat-transfer label assembly and to a new apparatus for applying heat-transfer labels to articles.
It is customary for manufacturers of garments and other finished fabrics (e.g., towels, bed linens, tablecloths, etc.) to attach thereto one or more labels that display various items of information, such as article size, fiber content, instructions for care, and the manufacturer's name or trademark. Such labels, which are to be contrasted with hanging price tags and the like, are typically not intended to be removed by the consumer after the purchase of the article, but rather, are intended to be permanently affixed to the article. In fact, such labels are commonly known in the industry as permanent care labels and typically comprise a small piece of cloth which is sewn directly onto the article, said small piece of cloth bearing the information described above.
Unfortunately, the presence of a permanent care label on certain articles, such as undergarments or other garments in which the label is in direct contact with the wearer's skin, can become irritating to the wearer. As a result, it is not uncommon for a wearer of such a garment to remove the permanent care label, typically by cutting or simply by ripping the permanent care label from the garment. However, as can readily be appreciated, such a practice not only results in a loss of the information contained on the label but the act of cutting or ripping the permanent care label from the garment can also result in significant damage to the garment, itself.
One approach to this problem has been to replace the aforementioned permanent care cloth label sewn onto the garment with a heat-transfer label applied to the garment. For example, in U.S. Patent Application Publication No. U.S 2005/0100689A1, inventors He et al., which was published May 12, 2005, and which is incorporated herein by reference, there is disclosed a heat-transfer label assembly that is well-suited for use in labeling fabrics. In one embodiment, the heat-transfer label assembly of the aforementioned patent application comprises a support portion, a wax layer, and a transfer portion. The support portion includes a carrier and a release coating, the release coating being applied to the top surface of the carrier. The wax layer is printed onto a desired area of the release coating. The transfer portion, which is printed directly onto the wax layer, comprises an adhesive layer printed directly onto the wax layer and an ink design layer printed directly onto the adhesive layer. The ink design layer may include a first portion that conveys fixed or non-variable information for a class of articles (e.g., manufacturer trademark, care instructions for articles differing only in size, etc.) and a second portion that conveys variable information that is specific to a single label or to a subset of labels. Examples of such variable information include serial numbers uniquely identifying each label; product characteristics, such as the size of each such article of clothing (e.g., S, M, L, etc.), style, fiber type, etc.; pricing information; identification or location of a manufacturer or distributor; and authenticity information. The non-variable information may be formed, for example, by screen printing, and the variable information may be formed, for example, using a variable printing technique.
The above-described heat-transfer label assembly may include a number of transfer portions (i.e., labels) positioned on a common support portion, the individual transfer portions being spaced apart from one another at regular intervals. For example, referring to FIG. 1, there is shown a perspective view of a heat-transfer label assembly of the type described above, said heat-transfer label assembly being shown partially wound into a roll and being represented generally by reference numeral 11. Assembly 11 comprises a carrier 13 and a release coating 15, release coating 15 being applied to the entire top surface of carrier 13. A plurality of wax areas 17 are printed at regular intervals onto the exposed surface of release coating 15. A heat-activatable adhesive layer 19 is printed directly onto an exposed area of each wax layer 17, and an ink design layer 21 is printed directly onto an exposed area of each adhesive layer 19, the combination of adhesive layer 19 and ink design layer 21 forming a transfer portion 23. (In another common type of heat-transfer label assembly, the adhesive layer is positioned over the ink design layer. A protective layer may additionally be positioned under the ink design layer.)
The transfer portion of a heat-transfer label assembly is typically transferred to an article using a heat-transfer label apparatus (also commonly referred to as a “bonder”). Examples of bonders include Avery Dennison Heat Transfer Bonder Model Nos. TH-2000 and M79200-00-3 (Avery Dennison Corporation, Pasadena, Calif.). In addition, a bonder is disclosed in U.S. Pat. No. 5,813,772, inventors Magill et al., which issued Sep. 29, 1998, and which is incorporated herein by reference. A conventional bonder typically includes a stationary pad and a movable, heated die. The stationary pad is typically flat and is made of a compressible material, such as silicone rubber. The movable die is also typically flat and is made of a rigid, heat-conductive material, such as aluminum. A motor is coupled to the die and is used to repeatedly move the die into contact with and out of contact with the pad.
Referring now to FIGS. 2(a) through 2(d), there is schematically shown the manner in which a fabric article A, such as a garment or other finished fabric, may be labeled using assembly 11 and a conventional bonder 51. First, as seen in FIG. 2(a), the article A is positioned on top of a flat pad 53 of bonder 51. Next, as seen in FIG. 2(b), a label assembly 11 is partially unwound from a roll, and one of the transfer portions 23 of assembly 11 is positioned over an area of article A that one wishes to label. Next, as seen in FIG. 2(c), a motor 54 moves a heated die 55 down towards pad 53 and into contact with label assembly 11, die 55 heating label assembly 11 and pressing label assembly 11 against article A and pad 53 in such a way as to cause transfer portion 23 to be transferred from the remainder of label assembly 11 to article A. (A portion of wax layer 17 may also be transferred with transfer portion 23 onto article A.) Next, as seen in FIG. 2(d), motor 54 moves heated die 55 upwardly away from the remainder of label assembly 11, as well as from the article A and pad 53, thereby leaving transfer portion 23 on the article A.
In general, the process described above works well; however, it is not uncommon for the process to result in an easily observable die-mark (i.e., impression) being left on the article over the entire area that was compressed between the heated die and the pad (see, for example, stippling representing die-mark 61 in FIGS. 3(a) and 3(b)). Such a die-mark is particularly perceptible on dark-colored articles and detracts from the appearance of the labeled article, especially on the reverse side of the article, where the die-mark is observable but the label is not. Moreover, because the reverse side of an article is often the exterior surface of the article (most garment labels being positioned on the interior surface of the garment), the appearance of a die-mark is particularly undesirable.
In addition to the undesired formation of die-marks, another problem associated with the process described above is that the label assembly, once wound into a roll, has a tendency to bond to itself (a phenomenon known in the industry as “blocking”). Such blocking may adversely affect the capacity of the roll to be unwound and/or may cause labels to be transferred to the back side of the carrier as the roll is being unwound (a phenomenon known in the industry as “pre-dispensing”).